White pine blister rust disease, caused by the introduced pathogen Cronartium ribicola, has severely disrupted five-needled pine ecosystems in North America. A 100-year effort to manage this disease was predicated in part on the premise that the pathogen utilizes only species of Ribes (Grossulariaceae) as...

Cronartium ribicola is a fungal pathogen that causes a blister rust disease of white pines, Ribes, and other hosts in the genera Castilleja and Pedicularis. Although blister rust can damage white pine trees and stands, the severity and significance of these impacts vary with time, place, and management. We use a natural history approach to describe the history, biology...

Limber pine (Pinus flexilis) is being threatened by the lethal disease white pine blister rust (WPBR) caused by the nonnative pathogen Cronartium ribicola. The types and frequencies of genetic resistance to the rust in native populations before invasion are likely to determine the potential success of restoration or proactive measures.

All nine species of white pines (five-needle pines) native to the United States are highly susceptible to Cronartium ribicola, the fungus causing white pine blister rust. The presence of genetic resistance will be the key to maintaining or restoring white pines in many ecosystems and planning gene conservation activities. Operational genetic...

Resistance to white pine blister rust based on a hypersensitive response (HR) that is conferred by a dominant gene has been identified as functioning in needles of blister rust-resistant families of sugar pine, western white pine and southwestern white pine. The typical HR response displays a characteristic local necrosis at the site of infection in the needles during...

Necrotic reactions in branch or main stems of western white pine (Pinus monticola Dougl.) caused by infection by the blister rust fungus (Cronartium ribicola J. C. Fisch. ex Rabenh.) are a major mechanism of resistance. Overall, 26 percent of the seedlings eliminated the fungus via this defense system. Heritability based upon crossing family groups averaged 33 percent...

White pine blister rust (WPBR) is caused by the fungal pathogen Cronartium ribicola. The pathogen is native to Eurasia and was introduced to North America early in the 20th century and is still spreading destructively throughout the range of native western white pines (Douglas ex D. Don) (McDonald and Hoff 2001). All of the North American five-needle (white) pines are...

White pine blister rust (Cronartium ribicola) causes extensive damage to white pines and their associated ecosystems across North America. The anatomical and cellular characteristics of C. ribicola colonization in Pinus monticola branch and stem tissues were studied as a basis for understanding host tree reactions that may be related to resistance. Samples examined...

Western white pine (Pinus monticola Douglas ex D. Don) is an important forest species in North America. Forest genetics programs have been breeding for durable genetic resistance against white pine blister rust (WPBR) caused by Cronartium ribicola in the past few decades. As various genetic resistance resources are screened and...

The white-pine blister rust fungus, Cronartium ribicola Fisch. in Rabenh., continues to spread in North America, utilizing various aecial (primary) and telial (alternate) hosts, some of which have only recently been discovered. This introduced pathogen has been characterized as having low genetic diversity in North America, yet it has demonstrated a...

Until recently, Cronartium ribicola J.C. Fisch. was thought to utilize only Ribes spp. (Grossulariaceae) as telial hosts in North America. During 2004, Pedicularis racemosa Dougl. ex Benth. and Castilleja miniata Dougl. (Orobanchaceae) were proven as natural telial hosts at a subalpine site (48...

The core distribution of Rocky Mountain bristlecone pine (Pinus aristata) extends from central Colorado into northern New Mexico with a disjunct population in northern Arizona (USA). Populations are primarily at high elevations and often define the alpine treeline, but the species is also found in open mixed-conifer stands with ponderosa (P. ponderosa) or pinyon (P....

Sequential sampling based on a negative binomial distribution of ribes populations required less than half the time taken by regular systematic line transect sampling in a comparison test. It gave the same control decision as the regular method in 9 of 13 field trials. A computer program that permits sequential plans to be built readily for other white pine regions is...

All nine species of white pines native to the U.S. or Canada are susceptible to the introduced pathogen Cronartium ribicola. Of the six high elevation white pine species, the severe infection and mortality levels of Pinus albicaulis have been the most documented, but blister rust also impacts P. aristata, P. balfouriana, P. flexilis and P. strobiformis; only P....

Presently, little is known about the worldwide genetic structure, diversity, or evolutionary relationships of the white-pineblister-rust fungus, Cronartium ribicola. A collaborative international effort is underway to determine the phylogeographic relationships among Asian, European, and North American sources of C. ribicola and...

The core distribution of Rocky Mountain bristlecone pine, Pinus aristata Engelm., extends from central Colorado into northern New Mexico, with a disjunct population on the San Francisco Peaks in northern Arizona. Populations are primarily at high elevations and often define the alpine treeline; however, the species can also be found in open mixed conifer stands with...

Western white pine (Pinus monticola) is an economically and ecologically important species from western North America that has declined over the past several decades mainly due to the introduction of blister rust (Cronartium ribicola) and reduced opportunities for regeneration. Amplified fragment length polymorphism (AFLP) was used...